javascript - 如何使用函数式编程遍历键映射并与另一个键映射进行比较

Question

我有 2 个关键映射，我想对其进行迭代。如果 key 相同，那么我想使用 _.assign() 来覆盖值。例如:

var keyMap1 = {
  1: {
    id: 1,
    name: 'egg'
  },
  2: {
    id: 2,
    name: 'bacon'
  }
};

var keyMap2 = {
  1: {
    id: 1,
    quantity: 3
  },
  2: {
    id: 2,
    quantity: 2
  }
};

// something like this, preferably with lodash 
var result = _.compareKeys(override, keyMap1, keyMap2);

function override(obj1, obj2){
   return _.assign(obj1, obj2)
}
console.log(result);
// => { 1: { id: 1, name: 'egg', quantity: 3 }, 2: { id: 2, name: 'bacon', quantity: 2 } };

Answer 1

如果我理解你的要求，你能不能只使用 _.merge 来进行比较和赋值？

var keyMap1 = {
  1: {
    id: 1,
    name: 'egg'
  },
  2: {
    id: 2,
    name: 'bacon'
  }
};

var keyMap2 = {
  1: {
    id: 1,
    quantity: 3
  },
  2: {
    id: 2,
    quantity: 2
  }
};

var result = _.merge({}, keyMap1, keyMap2);
console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.4/lodash.min.js"></script>